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Ravulizumab versus plasma exchange for acute neuromyelitis optica attacks: a randomized trial in patients with first or relapsed episodes

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

The study focuses on patients with neuromyelitis optica, a rare condition that causes sudden attacks affecting vision and movement. The trial compares two approaches used together with an intravenous corticosteroid treatment: an infusion of the drug ravulizumab and a procedure called plasma exchange. The purpose is to determine which approach provides a greater clinical benefit during an acute attack or relapse.

Participants are randomly assigned to receive either the drug infusion or the plasma exchange, both alongside the steroid medication. Over the following year, they undergo regular check‑ups that include vision testing with the Snellen scale (an eye chart), assessment of motor function using the EDSS score (a disability rating), quality‑of‑life questionnaires, and imaging scans with MRI (a technique that creates detailed pictures of the brain and spinal cord). Blood samples are also taken to measure disease‑related substances known as biomarkers. These visits allow researchers to track improvements, side effects, and overall health outcomes without providing technical details of the procedures.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Randomization and Baseline Evaluation

    After joining the study, you will be assigned at random to receive either ravulizumab or plasma exchange in addition to standard intravenous corticosteroid treatment.

    Before any treatment, a series of baseline measurements will be taken, including visual and motor function tests, blood samples for biomarker analysis, and magnetic resonance imaging (MRI) of the brain and spinal cord.

  2. Step 2

    Initial Treatment Administration

    If you are assigned to the ravulizumab group, you will receive a single intravenous infusion of 3600 mg of the drug, delivered through a vein over the prescribed infusion time.

    If you are assigned to the plasma exchange group, you will undergo a series of plasma exchange sessions performed according to the standard protocol for acute neuromyelitis optica, each session lasting several hours.

    All participants will also receive the standard intravenous corticosteroid regimen that is normally given for an acute attack.

  3. Step 3

    Day 15 Follow‑Up Visit

    Fifteen days after the initial treatment, you will return for a follow‑up visit.

    During this visit, visual and motor function will be reassessed, blood will be drawn to measure serum biomarkers (neurofilaments and GFAP), and any side effects or adverse events will be recorded.

  4. Step 4

    Month 1 Assessment

    One month after treatment, you will attend a clinic visit.

    Questionnaires will be completed to evaluate quality of life, fatigue, depression, and pain.

    Additional safety checks and blood sampling for biomarkers will be performed.

  5. Step 5

    Month 2 Comprehensive Evaluation

    At two months, a detailed assessment will be carried out.

    Visual and motor function will be measured again to determine whether there has been a significant improvement.

    An MRI scan will be performed to examine any changes in lesions.

    Blood samples will be taken for biomarker analysis, and quality‑of‑life questionnaires will be repeated.

  6. Step 6

    Month 6 Follow‑Up

    Six months after the start of the study, you will have another clinic visit.

    Visual and motor outcomes will be evaluated, an MRI scan will be repeated, and blood will be drawn for biomarkers.

    Quality‑of‑life, fatigue, depression, and pain questionnaires will be completed again.

    The study team will also review any hospitalizations, unscheduled visits, or sick leave related to the disease or its treatment.

  7. Step 7

    Month 12 Final Assessment

    At twelve months, the final study visit will occur.

    All previously used assessments will be repeated: visual and motor function tests, MRI imaging, biomarker blood draws, and quality‑of‑life questionnaires.

    A comprehensive review of any adverse events, hospital stays, or other health‑care utilization during the year will be documented.

    Data collected at this visit will be used to compare the overall benefit of ravulizumab versus plasma exchange as adjuncts to corticosteroid treatment.

Who can join the trial?

16 criteria

  • You must be 18 years old or older at the time you join the study.
  • If you are a woman who could become pregnant, you must not want to become pregnant and you must use reliable birth control for the whole study and for 8 months after the last dose of ravulizumab (a medication being tested).
  • You must be covered by the French social security system.
  • You need to be able to understand what the study involves and you must sign a written consent form.
  • You must be willing and able to follow all study visits and procedures for the entire study period.
  • You must have a diagnosis of neuromyelitis optica spectrum disorder (NMOSD) or an isolated attack on the spinal cord (myelitis) or optic nerve (optic neuritis) with a confirmed positive test for the antibody called AQP4‑IgG (a blood test that shows a specific protein linked to the disease).
  • You must be experiencing an active attack, meaning new or worsening neurological symptoms that started within the last 14 days.
  • You must not have improved enough after 5 consecutive days of high‑dose intravenous steroid treatment (5 × 1 g of methylprednisolone given through a vein each day). Intravenous methylprednisolone is a strong steroid medication given by drip.
  • You must have never received ravulizumab before joining the study (ravulizumab‑naïve).
  • Your score on the Expanded Disability Status Scale (EDSS) must be 7 or lower at screening. The EDSS is a scale that measures disability from 0 (no disability) to 10 (most severe).
  • If you are already taking medicines to prevent relapses (such as steroids, azathioprine, mycophenolate mofetil, methotrexate, tacrolimus, cyclosporin, or cyclophosphamide), you must have been on a stable dose for a set time before screening:
    • Azathioprine: at least 6 months total use and a steady dose for at least 2 months.
    • Other medicines listed (mycophenolate mofetil, methotrexate, tacrolimus): at least 3 months total use and a steady dose for at least 4 weeks.
    • Oral steroids: a steady dose for at least 4 weeks.
    • If you stopped any of these medicines recently, you must wait the same stable‑dose period (e.g., at least 2 months for azathioprine or at least 4 weeks for steroids) before the first day of screening.
    • If you are taking steroids, the daily amount must not exceed 0.5 mg per kilogram of body weight of prednisone (or an equivalent steroid) and must never be more than 20 mg per day.
    • You must have been vaccinated against meningococcal infection (caused by the bacteria Neisseria meningitidis) covering groups A, C, W135, and Y, either within the past 3 years or at least 14 days before the first dose of the study drug.

Who cannot join the trial?

24 criteria

  • If you have a known allergy (hypersensitivity) to the study drug ravulizumab, to mouse‑derived proteins (murine proteins), or to any of the inactive ingredients (called excipients) in the drug, you cannot join the study.
  • If you have received intravenous immunoglobulin (IVIg) or had a plasma exchange (PE) procedure within the three weeks before the screening visit, you are not eligible.
  • If a vision problem makes it impossible for you to sign the consent form or fill out study questionnaires on your own, you cannot participate.
  • If you have ever been infected with Neisseria meningitidis (the bacteria that can cause meningitis), you are excluded.
  • If you are currently taking part in another clinical trial that involves a new treatment, or have used any investigational drug within the required wash‑out period, you cannot join.
  • If you are pregnant, breastfeeding, or planning to become pregnant during the study period, you are not allowed to participate.
  • If you cannot have an MRI scan because of a non‑compatible implanted device (such as certain pacemakers) or severe fear of the scanner (claustrophobia), you are excluded.
  • If you cannot read or understand French well enough to follow the study instructions or give written consent, you cannot take part.
  • If you have a history of repeated infections that doctors cannot explain, you are not eligible.
  • If you have an active infection caused by bacteria, viruses, or fungi within 14 days before the first dose of the study drug, you cannot join.
  • If you have already been treated with ravulizumab before, you are excluded.
  • If you have a known deficiency in the complement system (a part of the immune system) or a history of repeated meningococcal infections, you cannot participate.
  • If you have already had a plasma exchange as the first treatment for the current attack of your disease, you are not eligible.
  • If tests show that you do not have the specific antibodies called anti‑AQP‑4 antibodies, you cannot join the study.
  • If you have any active infection at the time of screening, including a suspected or unresolved Neisseria meningitidis infection, you are excluded.
  • If you have not received the recommended meningococcal vaccination (vaccine against meningitis‑causing bacteria) before starting ravulizumab, and you are not taking preventive antibiotics as advised, you cannot participate.
  • If you are under a legal protection measure such as guardianship, trusteeship, or other court‑ordered protection, you are not eligible.
  • If you are known to be positive for human immunodeficiency virus (HIV), you cannot join the study.
  • If you were born with an immune system disorder (congenital immunodeficiency), you are excluded.
  • If you have had a fever of 38°C (100.4°F) or higher in the seven days before receiving the study drug, you cannot participate.
  • If the investigator believes you have a medical or psychological condition, or a risk factor, that could interfere with your full participation, increase your risk, or make the study results unclear, you are excluded.
  • If you have had any cancer (malignancy) within the past five years, except for skin cancers that are not melanoma or early‑stage cervical cancer that has been fully treated with no return, you cannot join.
  • If you have a known or suspected problem with drug or alcohol abuse or dependence within the past two years, based on standard diagnostic criteria (DSM‑5), you are excluded.
  • If you have taken the medication mitoxantrone within the three months before screening, you cannot participate.
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Investigated drugs

  • Ravulizumab

    is a specially designed antibody that blocks a part of the immune system called complement C5. By stopping this pathway, it helps reduce the severe inflammation that occurs during an attack of neuromyelitis optica. In the trial, it is given by a slow intravenous infusion through a vein.

  • Plasma exchange

    is a medical procedure used to treat acute attacks of neuromyelitis optica. Blood is taken out of the body, the liquid part (plasma) that contains harmful antibodies is removed, and the blood cells are returned with replacement fluid such as donor plasma or albumin. This helps lower the amount of disease‑causing antibodies in the bloodstream.

  • Intravenous corticosteroids

    are strong anti‑inflammatory medicines that are delivered directly into a vein. They act quickly to calm the immune response and reduce swelling in the nerves and spinal cord during an acute NMO episode. In the study, all patients receive this standard steroid treatment in addition to either ravulizumab or plasma exchange.

What is already known about the treatment

Ravulizumab - It is given by intravenous infusion as a concentrate that is mixed with a solution and delivered through a vein. The drug is an approved medicine for rare blood disorders and is now being studied for neuromyelitis optica, a rare nerve disease. It works by blocking a part of the immune system called complement C5, which helps reduce harmful inflammation. Ravulizumab belongs to the class of complement inhibitors, a type of biologic therapy.

Investigated diseases

Neuromyelitis optica spectrum disorder - a rare autoimmune condition that targets the optic nerves and spinal cord, leading to episodes of vision loss, eye pain, and weakness or numbness in the limbs. Attacks are typically sudden and can cause rapid worsening of visual and motor function. Between attacks, patients may recover partially, but repeated episodes can leave lasting deficits. The disease is associated with antibodies against the aquaporin‑4 water channel, which help define its diagnosis. It progresses through relapses and remissions, with each relapse potentially adding new neurological damage.
Trial detailsLast updated 14 Nov 2026
Age18+ yearsPhasePhase IIITrial ID2026-526632-39-00Protocol codeRC26_055Estimated enrolment30 patientsSponsorLes Hopitaux Universitaires De Strasbourg

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